In general, a conventional omnidirectional antenna comprises a dielectric core made of cylindrical ceramic, an electrical pattern line painted around the outer of the dielectric core in a spiral form, a conductive sleeve which is provided below the dielectric core and is connected with the pattern line, and an outer conductor which is passed through a hole formed in the dielectric core in contact with the conductive sleeve and connected with the top end of the painted line.
However, because the conventional antenna as described above is constructed by painting the electrical pattern line on the surface of the dielectric core, it has to be post-processed by adding plasticity processing, natural drying, or etching or laser processing after plating. Because of this, it has disadvantages of decreased productivity and increased production cost since a lot of processing time is consumed.